喜欢电话铃声的人可能对这种电路产生兴趣。它是利用电话铃信号来激励一个振荡器,而又激励一个工作于标准门铃声的继电器。振荡器是一个以4093施密特触发器(Sehmitt)为基础的RC型振荡器,C’的充电和放电时间采用预置来设定。振荡器之后是一个经T,激励继电器的缓冲器。电话铃信号被加到a、b两端,两通路中的电容C,和C。与隔直流电话网络电路相连接。为 People who like ringtones may be interested in this circuit. It is the use of telephone ring signal to stimulate an oscillator, but also inspire a relay operating in the standard doorbell sound. The oscillator is an RC oscillator based on a 4093 Schmitt-Trigger, with C ’charging and discharging times presetted. The oscillator is followed by a T, stimulating relay buffer. The telephone bell signal is applied to terminals a, b, capacitors C, and C in both circuits. Connected to the DC telephone network. for